1. Field of the Invention
The present invention relates to the storing and retrieving of monetary data. More specifically, the present invention relates to the storing of monetary data, such as data identifying electronic checks and electronic coins, in a storage medium, and to the later retrieval of the stored data by a means for electronic financial transactions, such as a smart card.
2. Discussion of the Background
Electronic checks and coins necessarily take up a fair amount of memory, as they include a variety of authentication data, such as a signature from a bank (issuer). Since the storage capacity of a smart card is usually limited, the need arises to store data externally while ensuring that the electronic money that is retrieved from storage can be trusted, i.e., that the data is valid. To accomplish this it is possible to arrange for use of an on-line protocol with the issuer each time data is loaded from storage. This is however time-consuming and often involves communications costs.